Symbolic and Hard Links are useful ways to reference to information on a disk, both found in UNIX and Linux systems. While they seem similar in the surface they are quite different in how they work and it what can be achieved when using them. If you find the articles in Adminbyaccident.com useful to you, […]
Symbolic and Hard Links in UNIX and Linux
How to upgrade MariaDB on FreeBSD
As we all know a best practice recommendation that has been made forever, and forever many are just skipping, is running up to date software and it is one of the core fundamentals of IT. If you happen to use MariaDB on FreeBSD, the official guide on their website may not be that all helpful […]
What is Expect?
Expect is a handy scripting tool for task automation. You may have never heard of it. I heard about many scripting things before. But one day I needed something simple but didn’t know how to proceed, what would be a good tool for my purpose. The task was simple. Exporting a website content from a […]
Abandon Linux. Rolling back the entire OS is possible.
When I was writing an article on updating FreeBSD from the 11.2 version to the new major release number 12, I was trying to add something extra for those who may read some of the information I publish. FreeBSD as a UNIX operating system has similar functionality to the old school UNIX ones such as […]
How to install software in FreeBSD with pkgng
The pkgng is the package management system in FreeBSD. It is used to install applications, and specific modules, libraries, etc. Nowadays you can select in between more than 25.000 thousand. Yes, twenty five thousand. The syntax to use is very intuitive and simple. As you may be already aware software comes in two forms. Source […]
Lynis or how to quickly audit your system’s security configuration
A colleague of mine pointed me out to Lynis, a system’s configuration audit tool which checks the hardening of any running UNIX or UNIX-like system, including the BSDs. This tool has a built in check list and a set of sane and safe configurations and compares them to the target system. As output we find […]
How to harden Apache HTTP
Disclaimer: This is a long article. I haven’t collected some nice configuration settings here for the sake of it. There are other hardening guides but some fall short on explaining the functionalities to be enabled or disabled. Every step is shortly, and hopefully clearly, explained so any reader can grasp the main idea of every […]
How to load and unload kernel modules in Linux
Kernel modules permit enabling hardware features on a given system. For example, if we need to read from a particular filesystem from a hard drive, we need to load a particular kernel module. Or use a specific network card, a sound card or sound device, a video display, etc. This is mostly done automatically in […]
Nessus vulnerability scanner
Nessus is a very well known vulnerability scanner used by many large and small companies to assess their systems and correct the issues found in them. Cybersecurity teams and specially auditors, make heavy use of tools like this in order to follow up the state of infrastructure and environments. Having a tool like this saves […]
How to patch OpenSSH in FreeBSD 12.2
The default version of OpenSSH in FreeBSD 12.2 today, and it’s been this for quite some time, is not the most recent published by the OpenBSD guys, which by the way are the ones developing OpenSSH. Not only is not the latest but it has a few vulnerabilities affecting it, medium risk ones but nevertheless […]